The present invention relates to a method and apparatus of removing moisture from air passing through an air cooling system and is an improvement over my prior U.S. Pat. No. 4,719,761 of Jan. 19, 1988 for a Cooling System.
My prior patent was a method and apparatus for increasing removal of moisture in a cooling system which provided for a desiccant to contact and evaporate moisture into the dry feed air prior to passing the feed air over cooling coils to increase the dew point or moisture content of the feed air. This increased the moisture removal of the cooling system. A desiccant material is loaded with moisture by absorption of moisture from the moisture saturated air leaving the cooling coils. The method included removing the moisture by desiccant from the saturated air leaving a cooling means and delivering the moisture to dry air entering the cooling means to increase the dehumidification of the cooling means. The improvements involve the handling of fresh air being brought into the cooling system from outside a building and the expungement of air from inside a building.
The air to be expunged is taken from the space within the cooling system directly after entering the system and passing through the desiccant coil but before the cooling coils of the cooling system. Fresh or make-up air is added at the same place in the cycle. Part of the air having increased moisture that has passed through the desiccant moisture transfer means, and which has had moisture added thereto, is used as the air that is to be expunged from inside the building. This allows an improvement in total moisture removal of the basic cooling system over simply expunging the indoor air because the air with increased moisture has a higher moisture content at this point. The indoor air is brought in adjacent the passageway for the expunged air and a further improvement in overall efficiency is achieved by adding a heat exchanger between the inlet for the outside air and the outlet air stream of the air being expunged from the system. This heat exchanger on the inlet and outlet air streams of the system is an improvement because the wetting process of the desiccant, by evaporation of water into the air stream, cools the air colder than the indoor air conditioned air used by existing heat exchangers. Thus, the heat exchange is improved and the load introduced by the fresh air is less than with existing heat exchangers.